gms | German Medical Science

Kongress Medizin und Gesellschaft 2007

17. bis 21.09.2007, Augsburg

Risk assessment and management of possible transmission of Lassa virus during two flights

Meeting Abstract

  • Tim Eckmanns - Robert Koch-Institut, Berlin
  • Andreas Gilsdorf - Robert Koch-Institut, Berlin
  • Daniel Reynders - SPF Santé Publique, Securité de la Chaîne Alimentaire et Environnement, Brüssel
  • Denis Coulombier - European Centre for Disease Prevention and Control, Solna
  • Franz Karcher - DG Sanco, Luxemburg
  • Gérard Krause - Robert Koch-Institut, Berlin

Kongress Medizin und Gesellschaft 2007. Augsburg, 17.-21.09.2007. Düsseldorf: German Medical Science GMS Publishing House; 2007. Doc07gmds078

The electronic version of this article is the complete one and can be found online at:

Published: September 6, 2007

© 2007 Eckmanns et al.
This is an Open Access article distributed under the terms of the Creative Commons Attribution License ( You are free: to Share – to copy, distribute and transmit the work, provided the original author and source are credited.



Objectives: Since the emergence of Lassa fever, reports of about 25 patients who imported Lassa virus to Europe, US or Canada have been published. More than 1,200 contacts were ascertained in these events and all remained pathogen free. On July 10th a person (patient) who flew from Freetown (Sierra Leone) to Frankfurt (Germany) via Brussels (Belgium) tested Lassa positive nine days after arrival in Germany. A risk assessment was conducted to guide the decision on a co-passenger trace back.

Methods: During the two flights the patient had no cough but a urinary tract catheter which was disconnected from the reservoir and released relevant amounts of urine on the passenger’s seat. The patient’s urine was tested positive for Lassa virus, which was taken into account for the risk assessment and contributed to the decision to trace back co-passengers potentially exposed.

The passengers at risk were defined as those sitting in maximum three rows distance from the patient. 92 passengers from nine countries were identified.

Results: In EU countries 29 (66%) of 44 contact passengers, in European non EU countries 7 (68%) of 9 passengers were traceable and from non European countries 0 of 27 passengers were traceable. Overall 62.4% of the contacts were traceable. Only one of the traced contacts developed symptoms but revealed to be Lassa negative.

Conclusion: In this investigation, the leakage from the urinary catheter reservoir influenced the risk assessment and the decision for a passenger trace back as Lassa fever is primarily transmitted by urine of rats. Nevertheless, no contact passenger revealed Lassa virus. Our investigation confirms that the human to human transmission of Lassa virus during flights is unlikely if no haemorrhagic symptoms appear at this time. Tracing back co-passengers remains a challenge internationally and stresses the need for an early voluntary implementation of the revised international health regulation.